1. Field of the Invention
The present invention relates to the improvement of a developer replenishing device that replenishes developer in proper quantity from the developer container to the developing unit attached to an image recording apparatus, and more particularly to the stirring means for the developer in the container or hopper of said developer replenishing device.
2. Description of the Prior Art
A developer to be used for image recording is prepared by mixing pigment or dye such as carbon black and other material with resins adapted to the mode of the image recording apparatus, or with magnetic substances such as iron powder depending upon said mode. It is a defect of the developer used for the dry development that it may become impossible to replenish the developer in the developing unit, by reason of the fact that by the adhesion of an active substance remaining on each fine grain developer, transmutation and transformation of each fine grain of the developer, or the influence of moisture, bridging or junction takes place between fine grains of the developer, and they gradually become lumps of grains. Another drawback is that a black spot appears on the image when a lump of grains drops into the developing unit and keeps its form.
It has been previously proposed that a stirrer having a special driving source is provided in the developer container in order to prevent the developer from becoming a lump of grains when it is left alone, but this is contrary to the desires of cost reduction, compactness and simplicity. There is an example in which a stirring disk having stirring claws that couple with a transporting member carrying the developer from the developer container to the developing section of the developing unit is arranged inside said developer container. However, circular stirring within the developer container surrounded by flat plates causes dead spaces where stirring can not reach and a stirring claw gives a checking effect to the toner in the form of the cylindrical chip laid on said stirring disk being divided by a stirring claw, thereby the stirring effect is insufficient and it is feared that the tendency to become a lump of grains from powder increases.